Bad overflow when editing multiline text

[mappu]

Hi, thanks for all your work on this library.

Using release v4.2.2, with Konsole 25.04 (or xterm), I have a problem with editing a multiline text, as soon as the input overflows onto a second line, it seems like there's some off-by-one with the character position. Editing is messed up and sometimes the whole second line will be re-printed.

My usage is only

rl := readline.NewInstance()
rl.SetPrompt("> ")
for {
    line, err := rl.Readline()